chemistry

in the titration the student used 25.0cm3 of sodium hydroxide.
this volume reacted with exactly 20.0 cm3 of 0.1 mol/dm3 of sulfuric acid solution.
2NaOH + H2SO4 Na2SO4 + 2H2O

What is the concentration in mol/dm3 of the sodium hydroxide solution?

Hiya,

1st you work out the moles of sulfuric acid as they've given you volume and concentration. Moles=concentration × volume. Moles = 20/1000×0.1 (always divide volumes by 1000 to convert from cm^3 to dm^3)

The NaOH and H2SO4 react in a 2:1 ratio from the diagram. So the moles of NaOH will be double the moles of H2SO4 you've worked out.

Then you can use concentration= moles/volume to find the concentration of NaOH used.

Hope this helps